validate_cron_expression

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description states the function is a validation check that returns errors, implying a read-only operation. However, since no annotations are provided, the description must disclose side-effect risks on its own; it does not explicitly state that no state is changed, nor does it mention any permissions or edge cases.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, front-loaded sentence that efficiently conveys the tool's purpose and key output behavior with no wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter tool with an output schema, the description covers the essential purpose and return behavior. It is slightly incomplete in not providing any usage guidance, but the low complexity keeps the gap small.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already documents the 'expression' parameter with 100% coverage. The description adds minimal semantic value beyond the schema, only clarifying that the expression is checked for syntactic validity.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool validates cron expressions and returns specific errors for invalid fields. This specific verb-resource pair (check + cron expression) distinguishes it from sibling tools like list_crontab, add_cron_entry, or explain_cron_expression.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied: validate an expression before using it in other cron tools. However, there is no explicit when-to-use or when-not-to-use guidance, nor any mention of alternatives (e.g., if you need an explanation, use explain_cron_expression).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.